Resonance Raman characterization of soluble guanylate cyclase expressed from baculovirus.
Resonance Raman spectra of the alpha 1 beta 1 isoform of bovine lung soluble guanylate cyclase expressed from baculovirus have been measured. The spectra show that the ferric heme is five-coordinate high spin whereas the ferrous heme in the absence of added exogenous ligands is a mixture of six-coordinate low spin and five-coordinate high spin. In the Fe-CO-derivative, the correlation between the Fe-CO frequency (497 cm-1) and the C-O frequency (1959 cm-1) demonstrates that the proximal ligand in our preparation is histidine. The Fe-NO stretching frequency (found at 520 cm-1) and other spectral features of the ferrous Fe-NO-bound sGC are similar to those reported by Deinum et al. (1) and Yu et al. (2). These data indicate that although large preparation-dependent differences in the occupancy of the distal pocket exist, all the preparations have the same proximal histidine ligation and share the same mechanism of activation by NO.
Fan
B
B
Department of Physiology and Biophysics, Albert Einstein College of Medicine, Bronx, New York 10461, USA.
Gupta
G
G
Danziger
R S
RS
Friedman
J M
JM
Rousseau
D L
DL
D000818:Animals; D016367:Baculoviridae / Q000201:enzymology / Q000235:genetics*; D002248:Carbon Monoxide; D002417:Cattle; D019281:Dimerization; D006162:Guanylate Cyclase / Q000096:biosynthesis / Q000737:chemistry* / Q000235:genetics*; D009569:Nitric Oxide; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000737:chemistry*; D012995:Solubility; D013059:Spectrum Analysis, Raman; D018411:Spodoptera / Q000235:genetics; D014162:Transfection
D011994:Recombinant Proteins; D009569:Nitric Oxide; D002248:Carbon Monoxide; D006162:Guanylate Cyclase